Means for changing the output of centrifugal compressors.



R. H. RICE.

MEANS FOR CHANGING THE OUTPUT 0F OENTRIFUGAL GOMPRESSORS.

AIPLIOATION FILED OUT. 3. 1911.

I 1,1 18,443. Patehted Nov. 24, 1914.

Wibnesses Inventor? I Richard 'H. Rice, 4

UNITED STATES PATENT OFFICE.

RICHARD H. RICE, OF WEST LYNN, MASSACHUSETTS, ASSIGNOR T0 GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

MEANS FOR CHANGING THE OUTPUT OF GENTRIFUGAL COMPRESSORS.

. Application filed. October 3, 1911.

To all whom it may concern:

Be it known that I, RICHARDH. RICE, a citizen of the United States,residing at West'Lynn, county of Essex, State of Massachusetts, haveinvented certain new and useful Improvements in Means for Changing theOutput of Centrifugal Compressors, of which the following is aspecification.

Centrifugal air compressors when .employed in the usual and normalmanner in blast furnace work, furnish a constant or substantiallyconstant number of cubic feet of free air per minute. There are times,however, when the amount of air required by the consumption devices isonly a fraction of the normal amount delivered by the compressor. Theproblem presented is, therefore, to provide agoverning mechanism for acompressor and its driving motor which is capable of being so adjustedor modified in its action, that the compressor instead of delivering itsnormal output, may deliver any fraction thereof at a predeterminedpressure. The adjusting or modifying means must operate in a simplemanner, requlre' little time to adjust and not necessitate shutting downthe apparatus or taking it apart in making said adjustment.

For a consideration of what I believe to be novel and my inventiomlattention is di: rected to the accompanying description and claimsappended thereto.

In the drawing is shown a centrifugal compressor and a turbine fordriving it, the compressor and turbine being shownside by side tosimplify the illustration.

1 ipdic'ates a driving motor. This may be a steamturbine of the Curtisor other type. It is provided with a regulator comprising a valve chest2, containin one or more valves that are actuated by t e cam shaft 3 inthe well-known manner. On the shaft is an arm 4; that is actuated by afloat located in the intake of the compressor.

5 indicates a part of the casing of a centrifugal compressor and 6 theintake therefor. Located within the intake pipeis afloat 7 Specificationof Letters Patent.

Patented Nov. 24:, 1914.

Serial No. 652,564.

that rises and falls as the rate of flow of air through the compressorvaries. The float operates in the manner set forth in my Patout 919,953,dated April 27, 1909, and this invention may be regarded as animprovement over that claimed in said patent.

- The structure of the patent is, however, arranged to deliver fluid atbut one predetermined constant rate of flow, whereas the structure ofthe present invention is arranged to deliver air at many different ratesof flow, each of which is constant when once established. The float 7 ismounted on a rod 8 thatextends upwardly through the top of the casingand is connected to the tilting scale beam 9. This beam is pivoted at 10on the bracket 11 and is provided with teeth or notches to hold a weightin position, as will appear later. The beam also has a suitable scale toguide the attendant in making adjustments. In the present instance as anillustration, a quadratic scale is provided and laid oil to indicatezero-flow, also a flow of twenty thousand, thirty thousand and fortythousand cubic feet of free air per minute. Connected to the beam is anarm 12 that is united by the rod 13 with the regulator of the motor, asfor example with the arm 4 on the cam shaft of the steam turbine. To theleft hand end of the beam is connected a rod 14 and piston 15, thelatter being located in the cylinder 16 and cooperating therewith toform a dash-pot. An adjustable by-pass 17 serves to regulate theell'ective action of the dash-pot.

Mounted on the right hand endof the beam 9, and adjustable thereon, is aweight 18 that counterbalanccs to a certain predetermined extent, theweight of the float 7, dash-pot parts,.etc. The remainder of the weightis supported by the fluid flowing upward through the intake. This weight18 is usually adjusted once for all when the parts are initiallyassembled. It correspondsin function to the weights 23 of myPatent 919953, aforesaid, but it has the *advantage of eing more readilyadjustaiglcQLWithinlividual weights supported as in said patent,considerable work may be involved 1n getting the exact balance desired.

The means for adjusting the mechanism to cause ditlerent but constantrates of flow of air at predetermined pressure to be delivered will nowbe considered.

Mounted on the notched scale beam 9 is an adjustable sliding weight 19having a suitable handle for moving it. When the weight 19 is in thezero-flow position and the weight 18 is in the proper position, theparts are balanced. Air flowing upward through the intake exerts a forceon the lever 9 through the rod 8, tending to move it upward. As theweight 19 is moved along the scale beam from the position shown, to-

- ward the left, the opposition to the upward movement of the float ischanged and the rate of flow of air through the compressor is thereforincreased. This is due to the fact that the changed position of theweight causes a depression of the left hand end of the beam and with itthe float 7 to a new and lower position. This action moves the regulatorof the motor in a direction to cause the speed of the motor to increase.Naturally as the speed of the motor increases, the impeller of thecompressorvwill rotate at a higher speed and discharge a greater amountof air per unit of time. The amount of air flowing through the intakewill, for any given condition, ultimately reach such a value as tobalance the effective action of the Weight 19 on the beam and when thisoccurs the speed of the driving motor will become substantially constantas will also the output of the compressor. This output is greater foreach successive position of the weightl toward the left from the initialposition. The parts are so proportioned and related, that a movement tothe left of the weight 19 steadily increases the rate of flow per unitof time until the maximum is reached when the pointer 21 will enter orcoincide with the notch in the scale beams indicating 40,000 cubic feetof free air. To decrease the rate of How, assuming the weight 19 to beset for maximum delivery, said weight is moved to the right whichpermits the float and cooperating beam to close one or more valves inthe turbine and decr ase its-speed.

The we ght of the dashpot rod 14 and piston 15, he float 7 and its red8, etc.. make the zero position of the weight 19 fall considerably tothe right of its pivot 10, as shown. and for ordinary ranges of velocitythis allovs the beam 9 to be pivoted about its middle instead of at ornear its left-hand end. This makes the apparatus more compact andconvenient.

The compressor illustrated is intended for a maximum output of 40,000cubic feet of free air per minute, but my invention is not limitedthereto asit is: capablebf wide ap- I plication.

- The scale beam occupies a substantially horizontal position at alltimes, and since patent statutes, I have described the principle of myinvention, together with the apparatus which I now consider to representthe best embodiment thereof; butl desire to have it understood that theapparatus shown is only illustrative and that the invention can becarried out by other means.

What I claim as new and desire to secure by Letters Patent of theUnitedStates, is,

. 1., The combination of a rotary compressor, a driving motor andregulating means therefor, a float located in a passage through whichthe fluid acted on by the compressor passes so as to float on the.flowing fluid and respond to variations in its rate of flow, a

rod'connectedwith said float and extending.

In accordance with the provisions of the,

through the-wall of said passage, a beam pivotally mounted on said wallto which said rod is connected intermediate its ends at one side of thepivot, a weight at one end of said beam for the purpose of initiallybalancing it under conditions of zero flow, an additional weightadjustable along said beam. to enable the device to be set so as tomaintain any desired rate of flow, said beam having on it a scale forindicating the rates of flow corresponding to various positions of saidlatter weight, a dashpot device comprising a stationary part secured tosaidwall and a movable part connected to said beam at the other end, andan operative connection joining said motor regulating means to said beamat a point intermediate between its ends.

2. The combination of a rotary compressor, a driving motor andregulating means therefor, a float located in a passage through whichthe fluid acted on by the compressor passes so as to float on theflowing fluid and respond to variations in its rate of flow, a-rodconnected with said float and extending through the wall of said passage, a pivotally mounted beam to which said rod is connected at oneside of the pivot. a weight on said beam for the purpose of initiallybalancing it under conditions of as to maintain any desired rate offlow, said my hand this Thirtieth day of September, beam hiving on it ascale for indicating the 1911. i rates 0 flow corresponding to variouspositions of said latter weight, and an opera- RICHARD RICE 5 tiveconnection between said beam and said Witnesses:

motor regulating'means. JOHN A. MCMANUS, J r.,

In witness whereof, I have hereunto set FRANK (x. HA'rrm.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents.

, Washington, D. 0.

